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Search: id:A073388
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| A073388 |
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Convolution of A002605(n) (generalized (2,2)-Fibonacci), n>=0, with itself. |
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+0
5
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| 1, 4, 16, 56, 188, 608, 1920, 5952, 18192, 54976, 164608, 489088, 1443776, 4238336, 12382208, 36022272, 104407296, 301618176, 868765696, 2495715328, 7152286720, 20452548608, 58369409024
(list; graph; listen)
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OFFSET
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0,2
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FORMULA
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a(n)=sum(b(k)*b(n-k), k=0..n) with b(k) := A002605(k).
a(n)=(2^n)*sum(binomial(n-k+1, 1)*binomial(n-k, k)*(1/2)^k, k=0..floor(n/2)).
a(n)= ((n+1)*U(n+1)+2*(n+2)*U(n))/6, with U(n) := A002605(n), n>=0.
G.f.: 1/(1-2*x*(1+x))^2.
a(n)=sum{k=0..floor((n+2)/2), k*binomial(n-k+2, k)2^(n-k+1)} - Paul Barry (pbarry(AT)wit.ie), Oct 15 2004
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CROSSREFS
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Second (m=1) column of triangle A073387.
Sequence in context: A127634 A115108 A127393 this_sequence A109634 A026126 A026155
Adjacent sequences: A073385 A073386 A073387 this_sequence A073389 A073390 A073391
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KEYWORD
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nonn,easy
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AUTHOR
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Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de), Aug 2, 2002
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